[v4 PATCH 05/12] spi/atmel_spi: update the dt support

Yang, Wenyou
2013-02-06T01:19:51Z

> -----Original Message-----
> From: Jean-Christophe PLAGNIOL-VILLARD [mailto:plagnioj at jcrosoft.com]
> Sent: 2013?2?6? 4:05
> To: Yang, Wenyou
> Cc: linux-arm-kernel at lists.infradead.org; linux-kernel at vger.kernel.org; Ferre,
> Nicolas; richard.genoud at gmail.com; Lin, JM
> Subject: Re: [v4 PATCH 05/12] spi/atmel_spi: update the dt support
>
> On 15:34 Mon 14 Jan , Wenyou Yang wrote:
> > To meet the different spi IP version of atmel SoC,
> > add the more compatible with different config and devtype.
> >
> > The "has_dma_support" is used to select the dma engine transfer mode.
> >
> > The "has_wdrbt" indicate if there is the "WDRBT" bit in the Mode Register,
> > WDRBT (Wait Data Read Before Transfer),if WDRBT is set,
> > a transfer can start only if the Receive Data Register is empty,i.e. does not
> > contain any unread data, to prevent overrun error in reception
> >
> > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
> > ---
> > drivers/spi/spi-atmel.c | 134
> ++++++++++++++++++++++++++++++++++++++++-------
> > 1 file changed, 115 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
> > index 8f6f0a0..43c1f63 100644
> > --- a/drivers/spi/spi-atmel.c
> > +++ b/drivers/spi/spi-atmel.c
> > @@ -71,6 +71,8 @@
> > #define SPI_FDIV_SIZE 1
> > #define SPI_MODFDIS_OFFSET 4
> > #define SPI_MODFDIS_SIZE 1
> > +#define SPI_WDRBT_OFFSET 5
> > +#define SPI_WDRBT_SIZE 1
> > #define SPI_LLB_OFFSET 7
> > #define SPI_LLB_SIZE 1
> > #define SPI_PCS_OFFSET 16
> > @@ -186,6 +188,12 @@
> > * DMA transfers; transfer queue progress is driven by IRQs. The clock
> > * framework provides the base clock, subdivided for each spi_device.
> > */
> > +struct atmel_spi_pdata {
> > + u8 version;
> > + bool has_dma_support;
> > + bool has_wdrbt;
> > +};
> > +
> > struct atmel_spi {
> > spinlock_t lock;
> > unsigned long flags;
> > @@ -204,6 +212,7 @@ struct atmel_spi {
> > struct spi_transfer *next_transfer;
> > unsigned long next_remaining_bytes;
> > int done_status;
> > + struct atmel_spi_pdata *pdata;
> >
> > void *buffer;
> > dma_addr_t buffer_dma;
> > @@ -218,6 +227,69 @@ struct atmel_spi_device {
> > #define BUFFER_SIZE PAGE_SIZE
> > #define INVALID_DMA_ADDRESS 0xffffffff
> >
> > +static struct atmel_spi_pdata at91rm9200_config = {
> > + .version = 1,
> > + .has_dma_support = false,
> > + .has_wdrbt = false,
> > +};
> > +
> > +static struct atmel_spi_pdata at91sam9260_config = {
> > + .version = 2,
> > + .has_dma_support = false,
> > + .has_wdrbt = false,
> > +};
> > +
> > +static struct atmel_spi_pdata at91sam9g45_config = {
> > + .version = 2,
> > + .has_dma_support = false,
> > + .has_wdrbt = true,
> > +};
> > +
> > +static struct atmel_spi_pdata at91sam9x5_config = {
> > + .version = 2,
> > + .has_dma_support = true,
> > + .has_wdrbt = true,
> > +};
> > +
> > +static const struct platform_device_id atmel_spi_devtypes[] = {
> > + {
> > + .name = "spi-at91rm9200",
> > + .driver_data = (unsigned long) &at91rm9200_config,
> > + }, {
> > + .name = "spi-at91sam9260",
> > + .driver_data = (unsigned long) &at91sam9260_config,
> > + }, {
> > + .name = "spi-at91sam9g45",
> > + .driver_data = (unsigned long) &at91sam9g45_config,
> > + }, {
> > + .name = "spi-at91sam9x5",
> > + .driver_data = (unsigned long) &at91sam9x5_config,
> > + }, {
> > + /* sentinel */
> > + }
> > +};
> > +
> > +#if defined(CONFIG_OF)
> > +static const struct of_device_id atmel_spi_dt_ids[] = {
> > + {
> > + .compatible = "atmel,at91rm9200-spi",
> > + .data = &at91rm9200_config,
> > + } , {
> > + .compatible = "atmel,at91sam9260-spi",
> > + .data = &at91sam9260_config,
> > + } , {
> > + .compatible = "atmel,at91sam9g45-spi",
> > + .data = &at91sam9g45_config,
> > + } , {
> > + .compatible = "atmel,at91sam9x5-spi",
> > + .data = &at91sam9x5_config,
> > + }, {
> > + /* sentinel */
> use the IP revision register to detect it
>
> IIRC 0xfc
>
Thanks for your feedback.
As the original comments, I need to check if this register exists on all chips.

> Best Regards,
> J.
> > + }
> > +};
> > +MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
> > +#endif
> > +
> > /*
> > * Version 2 of the SPI controller has
> > * - CR.LASTXFER
> > @@ -230,11 +302,12 @@ struct atmel_spi_device {
> > * register, but I haven't checked that it exists on all chips, and
> > * this is cheaper anyway.
> > */
> > -static bool atmel_spi_is_v2(void)
> > +static bool atmel_spi_is_v2(struct atmel_spi *as)
> > {
> > - return !cpu_is_at91rm9200();
> > + return as->pdata->version == 2;
> > }
> >
> > +
> > /*
> > * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby
> > * they assume that spi slave device state will not change on deselect, so
> > @@ -266,15 +339,21 @@ static void cs_activate(struct atmel_spi *as,
> struct spi_device *spi)
> > unsigned active = spi->mode & SPI_CS_HIGH;
> > u32 mr;
> >
> > - if (atmel_spi_is_v2()) {
> > + if (atmel_spi_is_v2(as)) {
> > /*
> > * Always use CSR0. This ensures that the clock
> > * switches to the correct idle polarity before we
> > * toggle the CS.
> > */
> > spi_writel(as, CSR0, asd->csr);
> > - spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS)
> > - | SPI_BIT(MSTR));
> > +
> > + if (as->pdata->has_wdrbt)
> > + spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MSTR)
> > + | SPI_BIT(MODFDIS) | SPI_BIT(WDRBT));
> > + else
> > + spi_writel(as, MR, SPI_BF(PCS, 0x0e)
> > + | SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
> > +
> > mr = spi_readl(as, MR);
> > gpio_set_value(asd->npcs_pin, active);
> > } else {
> > @@ -321,7 +400,7 @@ static void cs_deactivate(struct atmel_spi *as,
> struct spi_device *spi)
> > asd->npcs_pin, active ? " (low)" : "",
> > mr);
> >
> > - if (atmel_spi_is_v2() || spi->chip_select != 0)
> > + if (atmel_spi_is_v2(as) || spi->chip_select != 0)
> > gpio_set_value(asd->npcs_pin, !active);
> > }
> >
> > @@ -734,7 +813,7 @@ static int atmel_spi_setup(struct spi_device *spi)
> > }
> >
> > /* see notes above re chipselect */
> > - if (!atmel_spi_is_v2()
> > + if (!atmel_spi_is_v2(as)
> > && spi->chip_select == 0
> > && (spi->mode & SPI_CS_HIGH)) {
> > dev_dbg(&spi->dev, "setup: can't be active-high\n");
> > @@ -743,7 +822,7 @@ static int atmel_spi_setup(struct spi_device *spi)
> >
> > /* v1 chips start out at half the peripheral bus speed. */
> > bus_hz = clk_get_rate(as->clk);
> > - if (!atmel_spi_is_v2())
> > + if (!atmel_spi_is_v2(as))
> > bus_hz /= 2;
> >
> > if (spi->max_speed_hz) {
> > @@ -817,7 +896,7 @@ static int atmel_spi_setup(struct spi_device *spi)
> > "setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n",
> > bus_hz / scbr, bits, spi->mode, spi->chip_select, csr);
> >
> > - if (!atmel_spi_is_v2())
> > + if (!atmel_spi_is_v2(as))
> > spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
> >
> > return 0;
> > @@ -921,6 +1000,21 @@ static void atmel_spi_cleanup(struct spi_device
> *spi)
> > kfree(asd);
> > }
> >
> > +static struct atmel_spi_pdata * __devinit atmel_spi_get_driver_data(
> > + struct platform_device *pdev)
> > +{
> > + if (pdev->dev.of_node) {
> > + const struct of_device_id *match;
> > + match = of_match_node(atmel_spi_dt_ids, pdev->dev.of_node);
> > + if (!match)
> > + return NULL;
> > + return (struct atmel_spi_pdata *) match->data;
> > + }
> > +
> > + return (struct atmel_spi_pdata *)
> > + platform_get_device_id(pdev)->driver_data;
> > +}
> > +
> > /*-------------------------------------------------------------------------*/
> >
> > static int atmel_spi_probe(struct platform_device *pdev)
> > @@ -987,11 +1081,21 @@ static int atmel_spi_probe(struct
> platform_device *pdev)
> > if (ret)
> > goto out_unmap_regs;
> >
> > + as->pdata = atmel_spi_get_driver_data(pdev);
> > + if (!as->pdata)
> > + goto out_unmap_regs;
> > +
> > /* Initialize the hardware */
> > clk_enable(clk);
> > spi_writel(as, CR, SPI_BIT(SWRST));
> > spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround
> */
> > - spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
> > +
> > + if (as->pdata->has_wdrbt)
> > + spi_writel(as, MR,
> > + SPI_BIT(MSTR) | SPI_BIT(MODFDIS) | SPI_BIT(WDRBT));
> > + else
> > + spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
> > +
> > spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
> > spi_writel(as, CR, SPI_BIT(SPIEN));
> >
> > @@ -1084,21 +1188,13 @@ static int atmel_spi_resume(struct
> platform_device *pdev)
> > #define atmel_spi_resume NULL
> > #endif
> >
> > -#if defined(CONFIG_OF)
> > -static const struct of_device_id atmel_spi_dt_ids[] = {
> > - { .compatible = "atmel,at91rm9200-spi" },
> > - { /* sentinel */ }
> > -};
> > -
> > -MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids);
> > -#endif
> > -
> > static struct platform_driver atmel_spi_driver = {
> > .driver = {
> > .name = "atmel_spi",
> > .owner = THIS_MODULE,
> > .of_match_table = of_match_ptr(atmel_spi_dt_ids),
> > },
> > + .id_table = atmel_spi_devtypes,
> > .suspend = atmel_spi_suspend,
> > .resume = atmel_spi_resume,
> > .probe = atmel_spi_probe,
> > --
> > 1.7.9.5
> >

Best Regards,
Wenyou Yang